What it really costs to charge an EV
An EV "fill-up" is measured in kilowatt-hours (kWh), not gallons — and once you know how many kWh you need and what your power costs, the math is short. The bigger surprise is how much the place you charge changes the price.
The formula
Cost is kWh used × price per kWh. To get kWh, either use the battery size for a full charge, or work from distance and efficiency:
kWh = miles ÷ efficiency (mi/kWh)
cost = kWh × price per kWh
Drive 250 miles at 3.5 mi/kWh and you need about 250 ÷ 3.5 = 71 kWh. At a
home rate of $0.16/kWh that's roughly 71 × 0.16 = $11.40 — for 250 miles.
Worked example: one week of commuting
Say you drive a 2023 Tesla Model 3 Standard Range (rated around 3.5 mi/kWh in mixed driving) and commute 60 miles round-trip, five days a week.
- Weekly miles: 60 × 5 = 300 miles
- kWh needed at the battery: 300 ÷ 3.5 = 85.7 kWh
- Account for charging losses (10%): 85.7 ÷ 0.90 = ~95 kWh drawn from the wall
- Home rate at $0.15/kWh: 95 × $0.15 = $14.25/week
- Monthly estimate: ~$14.25 × 4.3 = ~$61/month
For the same 300 miles in a 30-MPG gas car at $3.50/gallon: (300 ÷ 30) × 3.50 = $35/week,
or roughly $150/month. Home-charged electricity is often less than half the per-mile fuel cost of
a typical gas car — though the gap narrows or reverses at DC fast chargers.
Use the EV Charging Cost Calculator to run your own numbers, and the EV vs. Gas Calculator to compare total fuel cost head-to-head against a gas vehicle.
Where you charge changes everything
The formula is the same regardless of where you plug in — what changes is the price per kWh and, sometimes, the billing unit itself.
- Home (Level 1 or 2): almost always the cheapest, and cheaper still on an overnight/off-peak rate. This is where most EV charging happens.
- Public Level 2: sometimes free (shopping centers, workplaces), sometimes priced per kWh or per hour — generally more than home, often $0.25–$0.40/kWh.
- DC fast charging: the most expensive per kWh, and the gap from home rates can be large — $0.40–$0.65/kWh or more at many networks. Great for road trips, pricey as a daily habit.
Quick-reference: typical charging costs
| Charging type | Typical rate | Cost per 100 miles (3.5 mi/kWh) |
|---|---|---|
| Home (off-peak) | $0.10–$0.14/kWh | $2.90–$4.00 |
| Home (peak) | $0.14–$0.22/kWh | $4.00–$6.30 |
| Public Level 2 | $0.25–$0.40/kWh | $7.10–$11.40 |
| DC fast charge | $0.40–$0.65/kWh | $11.40–$18.60 |
Rates shown are typical national ranges; your utility and region will differ. Some DC fast networks also charge a per-minute fee once the session reaches 90% state-of-charge, which can push effective cost higher if you stay plugged in.
What moves your efficiency (mi/kWh)
Efficiency is the EV version of MPG — and like MPG it isn't fixed. The same car can vary noticeably depending on conditions.
- Cold weather: lithium-ion batteries lose capacity and resist fast charging in sub-freezing temperatures. Real-world range can drop 20–40% in deep cold.
- Highway speed: aerodynamic drag rises with the square of speed. Steady 75 mph highway driving cuts efficiency significantly compared to mixed-speed driving.
- Heat and AC: cabin heating is the bigger drain (it can't recycle engine waste heat the way a gas car does). AC is less costly but still real.
- Regenerative braking: stop-and-go city driving often returns more energy than steady highway cruising — counterintuitively, many EVs have better mi/kWh in the city.
Use your car's recent average from the trip computer when you have it. The EPA's stated efficiency is a useful baseline but tends to be optimistic for highway-heavy routes.
Should you charge at home or on the road?
For daily use, charging at home overnight — especially on a time-of-use rate that prices off-peak electricity cheaper — is almost always the lowest-cost option. A 240V Level 2 home charger adds roughly 20–30 miles of range per hour, so an overnight session covers most commute patterns without any planning.
DC fast charging on road trips is a different calculation. The higher per-kWh cost is the price of convenience and speed — a 150 kW charger can add 100+ miles of range in 20–30 minutes. For occasional long trips, the cost premium is usually worth it. As a substitute for home charging for daily driving, it isn't.
Common mistakes
- Using the battery's total size instead of usable capacity. Manufacturers rate pack size at total capacity; most EVs reserve 5–10% at top and bottom to protect cell life. The usable range is slightly smaller than the headline number implies.
- Ignoring charging losses in the math. The wall meter ticks for every kWh that flows — including the ~10% lost as heat before it reaches the battery. Skip this and you consistently underestimate your electricity bill.
- Treating the EPA range as a reliable road-trip budget. EPA numbers use a standardized test cycle. Cold weather, steady 75 mph highway speed, and a loaded vehicle can each cut real range by 15–25% independently.
- Comparing home electricity to gas at the pump without accounting for home charging convenience. The cost advantage of home charging is real — but the comparison should also factor in the charger installation cost amortized over years, not just rate vs. pump price.